Web feeding method and apparatus



June 11, 1968 PEABODY, JR 3,387,429

WEB FEEDING METHOD AND APPARATUS Filed Aug. 28, 1964 4 w a m a i 6 Z M wW D m H F a m i L x a m e w mm T a 0 d T FIGJ FIG.3

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ATTORNEYS United States Patent 3,387,429 WEB FEEDlNG METHOD ANDAPPARATUS William Alden Peabody, Jr., Hcurico County, Va, as-

signor to Reynolds Metals Company, Richmond, Va a corporation ofDelaware Filed Aug. 28, 1964, Ser. No. 392,740 7 Claims. (Cl. 53-228)ABSTRACT OF THE DISCLQSURE Automatic or semi-automatic machinery forwrapping articles such as cigarette packages in a transparent overwrap.In particular, the invention is directed to the proper feeding of thingauge, and often flimsy, wrapping material into the path of the articlesto be wrapped, and efficiently retaining the same thereat by a subjacentsuction device until wrapping commences.

This invention relates to web feeding devices and more particularly toimproved methods and apparatus for effectively feeding and guiding verythin and flimsy plastic webs in association with high speed packagewrapping machines.

In the wrapping of articles, such as cigarette packages, it isconventional in the industry to feed a relatively thick and stiff web ofwrapping material such as Cellophane in a vertical direction downwardlythrough a web-receiving slot in an article support platform to therebydispose the web transversely of and in the path of an advancingcigarette package, which latter engages the web above the leading endthereof to effect a U-fold about the package as the package continuesits motion, after which further folding and sealing operations takeplace on the wrapper. One example of such conventional machinery isshown in Forster Patent 2,266,362.

In recent years, there has been a trend away from the use of relativelystill. or thick Cellophane-like material toward less expensivetransparent wrapper webs such as polyvinyl chloride (PVC) orpolyethylene which in addition to their economic advantages, are heatsealable, heat shrinkable, and have other desirable characteristics.Such materials, however, are quite thin and flimsy in nature, commonlyhaving a thickness on the order of /2 or mil. As a result, considerabledifficulty has been encountered in feeding such webs on conventionalhigh speed Wrapping apparatus of the type above briefly referred to.Thus, while Cellophane may be temporarily further stiffened for feedingby imparting a gently vertically corrugated configuration thereto whilevertically delivering the same to insure proper straight-line feedthereof, such stiffening as by corrugating cannot be effectivelyimparted to a filmsy /2 mil PVC web or the like. Further, in being fedover and through various feeding and cutofl rolls, there is an increasedtendency of these extremely thin plastic films to acquire a staticcharge which causes these lightweight films to depart from theirintended feed path and cling to or otherwise become entangled withportions of the machine, necessitating shutdown of the apparatus tocorrect these difiiculties with resultant expense and loss of time.

'I have found that with the cooperative association of several novel andimproved feeding means that these aforementioned difficulties can beeliminated, whereby such flimsy webs may be readily and speedily fed,and can be readily incorporated into existing apparatus without majormodification thereof.

It is therefore an object of this invention to provide improved feedingmeans for insuring the proper vertical feed of flexible flimsy webs suchas /2 or /1 mil PVC or the like.

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It is a further object of the invention to insure that the web will befed truly vertically and will not become enmeshed with or wrapped aroundportions of the machine.

It is a further object of my invention to provide novel and simplecontrolled air flow means to facilitate guidance of the web.

Another object of my invention contemplates the use of the article beingwrapped, such as the cigarette package itself, as a valve means tocontrol the: air flow at the proper time in a wrapping cycle.

Additionally, it is an object of my invention to provide a simplemechanical air flow valve control means which may be readilyincorporated into existing machinery to insure proper feeding of the webwithout tangling or jamming thereof.

Further objects and advantages of my invention will be apparent from thefollowing detailed description taken in connection with the accompanyingdrawings, in which:

FIG. 1 is a diagrammatic side elevation of a preferred form of myinvention;

FIG. 2 is an enlarged fragmentary detail of a timing valve employed inthe apparatus of FIG. 1;

FIG. 3 is a fragmentary perspective View showing the O-belt feed meansfor the Web;

FIGS, 4, 5 and 6 are fragmentary diagrammatic illustrations ofsuccessive stages in the initial wrapping of a package according to myinvention.

Referring to the drawings, there is shown at 10 a web of flimsytransparent plastic film such as /2 or mil thickness polyvinyl chloride(PVC) supplied from a suitable source such as illustrated in the abovementioned Foster patent. The web 10 is fed vertically downwardly bycooperating reaches of Oring feed belts l2 trained respectively aboutupper and lower pairs of grooved rollers 14 and 16, of which one pair isdriven by suitable means. The web passes thence between a rotatableknife 18 and cooperating anvil 20 which at timed intervals effect theseverance of a length of film from the web for wrapping the package 22.The package is advanced in conventional fashion in timed relation acrossa platform 24, which latter is provided with a transverse slot 26 inalignment with the direction of web feed and through which the leadingend of the web is fed. Suitable suction means are provided incommunication with the lower end of the slot 26, including a verticallength of conduit 23 detachably afiixed to platform 24 and a horizontalconduit which communicates with a vacuum pump device, such as a blowerfan 32, which is driven in a direction to produce a negative pressure inthe conduit sections 28 and 30 resulting in a downward air flow throughslot 26.

In the preferred form of my invention I incorporate a butterfly valve34, FIG. 2, in the conduit 30 mounted upon a rotatble shaft 36journalled therein. A crank arm 38 affixed to shaft 36 is provided atits remote end with a laterally extending stud 40 which is slidablyreceived within the slotted end of a lever 42. Lever 42 is pivotallymounted upon an arm 44, which along with conduit support 46 are afiixedto a suitable base 48. The other end of lever 42 carries a cam followerroller 50 which is maintained in rolling engagement with a driven cam 52by means of tension spring 54 affixed between lever 42 and a framemember of the machine, such as platform 24. The cam 54 in mounted upon ashaft 56 and is driven by suitable motor means in timed relation withother operations of the web feeding apparatus to effect opening andclosing of the butterfly valve 34 in a manner to' be hereinafterexplained.

A suitable anti-static device 58 of the ionizing needle point type islocated between the feed belts 13 and the cutter 18 to minimize theelectrostatic charge on the web. The precise location of the anti-staticdevice relative to the web may be varied for optimum efficiency and morethan one device may be used on the machine as desired.

It will thus be seen that the flimsy web in is gripped between theconfronting runs of the several spaced O-belts 12 and is positively feddownwardly toward the slot 26 between the cutter 18 and anvil 20.

Accordingly, with the valve 34 in substantially open position as the camfollower roller 5! traverses the shorter radius portions of cam 52,suction is drawn through conduits 28 and 30 whereby the resultant airflow above platform 24 insures that the leading end of the web deliveredfrom feed belts 12 will be positively led between cutter and anvil 18,20 and thence downwardly through the slot 26. A slight flutter or rippleindicated at F, is imparted to the flimsy web by the suction-induced airflow, whereby the plastic film material which is inherently of asomewhat clinging nature will be prevented from attraction and adherenceto adjacent portions of the apparatus, such as cutter 1S, anvil 2t],shoe 60, or the sides of the platform slot 26.

As the leading end of the web 10 initially enters slot 26, the article22 is being advanced theretoward across platform 24 by conventionalmeans, and the butterfly valve 34 is at this time in open positioncausing the moving film of air to assist the leading edge of the film topass downwardly and into slot 26 as seen in FIGS. 1 and 4. As thepackage 22 approaches and transversely engages the web, as seen in FIG.5, the high portion 62 of cam 52 elevates cam follower roller to therebyclose valve 34, and thus terminating downdraft suction on the film asthe package 22 passes from the FIG. 5 to the FIG. 6 position. In thepreferred embodiment, it is important that the timing of the valve besuch that suction is cut off at this point in the wrapping cycle so asto insure a neat and properly aligned initial U-fold and to preventexcessive fiutter of the film as the package passes over slot 26 toengage and carry the film therewith. If the air flow induced film rippleis excessive at this point the film 10 will not necessarily neatlyU-fold about the package 22, but will tend to become inturned andunderfolded at the edges or corners of the package, and the thusinturned film will tend to remain askew as the package passes betweenthe shoe and the table 24 therebeneath, thereby preventing subsequentproper final folding and wrapping operations.

At the FIG. 6 position, however, just prior to the complete initialU-wrapping of the package and just before knife 18 has severed apackage-length sheet from the web 10, cam follower roller 50 rides fromthe high portion 62 of the cam onto the lower portion thereof togradually open valve 30 and reestablish suction on the film. Thus, whenknife 18 severs a package-length sheet from the web, which occurs at orimmediately after the position shown in FIG. 6, the film is againsubjected to downdraft suction through slot 26, thereby insuring thatthe newly formed leading edge of the web 10 will be led downwardlytoward the slot and will not tend to adhere in clinging electrostaticcontact with revolving knife blade 18 or cling to other adjacentmembers.

Accordingly, it will be seen that the downdraft suct on is maintainedthrough slot 26 for a major part of the interval between two successivepackage wrapping operations and indeed about of the time intervaltherebetween, and constitutes a principal and novel, yet mechanicallysimple, means of successfully effecting wrapping operations withhitherto virtually unworkable flimsy films.

With the apparatus just described, I have found that conventionalpackaging machinery available on the market, such as the Scandia Model708 Cigarette wrapping machine, as modified in accordance with theteachings of my invention, is capable of feeding flimsy plastic films ofextreme thinness such as /2 mil solution cast biaxially oriented PVC orthe slightly thicker mil PVC at normal full operative speeds of themachine on the order of i packages per minute commonly employed withconventional Cellophane overwrap webs, without jam-ups or misfeeding dueto the previous inability of these extremely light gauge flimsymaterials to feed reliably in a vertically downward direction.

Indeed, while in the preferred embodiment of the invention I have shownthe suction conduit and blower as including a cyclically operated timingmeans including butterfly valve 34, I have found that flimsy webs may bereasonably successfully fed even without a separate mechanicallyoperated suction control valve. In this latter instance, the passage ofthe package 22 over slot 26 cffectively serves to valve the downdraftair flow, inasmuch as the package 22 fully blocks slot 26 in passingthereover except for the extreme transverse side edges thereof, whereinthe package itself thus acts as a valve in carrying out the purposes ofmy invention. In such instances, it is preferable to employ a pluralityof antistatic devices 58 to minimize electrostatic attraction, and tooperate the vacuum blower at a slightly lower speed to minimize edgeflutter of the web. Thus as the package 22 arrives at the position ofFIG. 5, the slot 26 is already partially blocked, and as the packagepasses from the FIG. 5 to the FIG. 6 position, the slot is almost fullyblocked permitting the film material to wrap about the package withoutexcessive tendency for the now severed film length to be sucked intoconduit 23. As the U-wrapped package commences leaving the area of theslot 26 as seen in FIG. 6, and the trailing end of the package fullyreopens the slot, the full downdraft suction will be re-established,thereby insuring that the newly formed leading edge of the filmfollowing severance thereof by knife 13 will be properly fed down intoand through the slot prior to arrival of the next package.

While I have shown in FIG. 1 the use of two confronting arrays ofO-belts 12 for feeding the film, the same are not strictly necessaryexcept that quite thin and flimsy films such as /2 mil PVC. For slightlythicker films such as mil PVC, although still substantially thinner thanconventional Cellophane, a single series of O-belts 12 is all that isstrictly necessary, and the material can be fed thereby in cooperationwith conventional pleater means in lieu of a corresponding set ofO-belts.

I claim: 1. In a web feeding device for a wrapping machine, including,

conveying means for vertically feeding a web, cutoff means disposedbeneath said conveying means for severing a package length sheet fromsaid web,

platform means spaced beneath said cutoff means over which an article tobe wrapped is advanced, said platform having a transverse slot disposedin the web feed path and through which the leading end of said webpasses, and means for advancing said article over said platform in timedrelation to said conveying and cutoff means to cause said article toengage said web at said slot above the leading edge thereof thereby toU-fold a severed sheet length of said web about said article,

the improvement therein for feeding webs of thin and flimsy material,comprising suction means cooperatively associated with said transverseslot therebeneath for creating a downdraft therethrough for guiding theleading edge of a flimsy web theretoward, and for imparting flutter tosaid web to prevent clinging adherence of said web to adjacent portionsof said device.

2. The device of claim 1 further including a valve for controlling saidsuction means, and means for operating said valve in timed relation tosaid article-advancing and cutoff means to terminate said downdraftsubstantially while said article advances across said slot and toreestablish said downdraft prior to web severance.

3. The device of claim ll wherein said suction means includes a conduitcommunicating at one end with said slot and at its other end with asuction-producing means, said conduit having therein between the endsthereof a valve for controlling the downdraft suction present at saidslot,

and cam means for operating said valve in timed relation with saidarticleadvancing and cutoff means.

4'. The device of claim 3 wherein said cam means effects closing of saidvalve to terminate said downdraft suction as said article advances overszid slot into contact with said web, and said cam means effects openingof said valve as the trailing edge of said package passes over said slotand immediately prior to the time said cutoff means severs a sheet fromsaid web, wherebyexcessive suction-induced flutter as said articlepasses over said slot is prevented and said downdraft suction isreestablissed to positively guide the newly formed Web end to said slot.

5. Apparatus for feeding a flimsy Web in a wrapping machine, comprising,

conveying means for feeding the web downwardly in a vertical path,

cutoff means disposed below said conveying means for severing a wrappersheet from said web,

a platform disposed beneath said severing means in spaced relationthereto for receiving articles to be wrapped, said platform having atransverse slot therein aligned with said web path,

and means for creating a downdraft air flow through said slot forguiding the free end of said web theretoward to thereby dispose said webin the path of an article on said platform to be wrapped.

6. The device of claim 5 wherein said conveying means comprises aplurality of pairs of endless belts, each said pair thereof havingadjacent cooperating reaches between which said flimsy web is grippedand fed along said vertical path.

7. Apparatus for feeding a flimsy web in a wrapping machine, comprising,

conveying means for feeding the web downwardly in a vertical path,

cutoff nietans disposed below said conveying means for severing apackage sheet from said web,

a platform disposed beneath said severing means in spaced relationthereto for receiving articles to be wrapped, said platform having atransverse slot therein aligned with said web path,

means for creating a downdraft air flow through said slot for guidingthe free end of said. web theretoward to thereby dispose said web in thepath of an article to be wrapped and to impart flutter to said web toprevent clingin. thereof to aid apparatus, eans for successivelyadvancing articl s across said platform, over said slot and into saidweb transverse- 1y thereof to cause said web to U-fold about anadvancing article,

and means for operating said cutoff and advancing means in timedrelation to cause said cutoff means to sever a sheet from said websubsequent to passage of the leading end of said article over said slotto thereby prevent said downdraft air flow from drawing said severedsheet through said slot.

References flited UNITED STATES PATENTS 1,847,915 3/1932 Bailey 271-74 X3,274,870 9/1966 Schrnermund 83-100 X 3,277,630 10/1966 Youngman et a1.53-389 3,307,327 3/1967 Liedtke 53-230 FOREIGN PATENTS 923,002 4/1963Great Britain.

WILLKAM W. DYER, 11L, Primary Examiner.

N. ABRAMS, Assistant Examiner.

